I think Russia's problem is it spent its entire history surrounded by powerful enemies, and was frequently invaded. As a consequence Putin honestly believes NATO has the intention of invading it, and so he thinks Russia has to take aggressive actions to prevent that.

What he doesn't get is that, thanks to nuclear weapons and modern industrialization, NATO is not interested in doing that for either reasons of security or wealth. That is why, when the Cold War ended, NATO nations drastically cut their arms budgets. NATO would like to basically leave Russia alone, but Russia's agressive actions are forcing it to respond.